Emmy Noether Research Group, Department of Physics, Darmstadt University of Technology, Hochschulstraße 6, D-64289 Darmstadt, Germany.
J Phys Condens Matter. 2010 Dec 15;22(49):495401. doi: 10.1088/0953-8984/22/49/495401.
A theoretical framework for dislocation dynamics in quasicrystals is provided according to the continuum theory of dislocations. Firstly, we present the fundamental theory for moving dislocations in quasicrystals giving the dislocation density tensors and introducing the dislocation current tensors for the phonon and phason fields, including the Bianchi identities. Next, we give the equations of motion for the incompatible elastodynamics as well as for the incompatible elasto-hydrodynamics of quasicrystals. We continue with the derivation of the balance law of pseudomomentum thereby obtaining the generalized forms of the Eshelby stress tensor, the pseudomomentum vector, the dynamical Peach-Koehler force density and the Cherepanov force density for quasicrystals. The form of the dynamical Peach-Koehler force for a straight dislocation is obtained as well. Moreover, we deduce the balance law of energy that gives rise to the generalized forms of the field intensity vector and the elastic power density of quasicrystals. The above balance laws are produced for both models. The differences between the two models and their consequences are revealed. The influences of the phason fields as well as of the dynamical terms are also discussed.
根据位错连续体理论,为准晶体内位错动力学提供了一个理论框架。首先,我们给出了准晶体内运动位错的基本理论,给出了位错密度张量,并引入了声子和拟相位场的位错电流张量,包括比安基恒等式。接下来,我们给出了非协调弹性动力学以及准晶体非协调弹流动力学的运动方程。我们继续推导出赝动量的平衡定律,从而得到准晶体的广义 Eshelby 应力张量、赝动量矢量、动力学 Peach-Koehler 力密度和 Cherepanov 力密度的形式。还得到了直线位错的动力学 Peach-Koehler 力的形式。此外,我们推导出能量平衡定律,从而得到准晶体的场强向量和弹性功率密度的广义形式。上述平衡定律适用于这两种模型。揭示了两种模型之间的差异及其后果。还讨论了拟相位场和动力学项的影响。